My dog is throwing up water. He can’t seem to keep it down. He’s a 14-year-old Shih Tzu named Jack. He’s always had a sensitive stomach. But now he laps up an entire bowl of water, walks around a bit, and spontaneously vomits, sometimes in mid-stride. When it comes back up, it’s still clear, but it’s no longer water-as-we-know-it. It’s mucus-y and thick – mixed with stomach bile, petroleum jelly, or some alien plasma goo, I don’t know.